This invention relates to a novel fluorine derivative of vitamin D.sub.3. More particularly, it relates to a novel fluorine drivative of vitamine D.sub.3 which not only has an excellent pharmacological activity, namely a useful vitamine D-like physiological activity, and is useful as a curative or preventive medicine for various diseases caused by disorders of absorption, transportation or metabolism of calcium, for example bone diseases such as rickets, osteomalacia and osteoporosis, but also has an ability to suppress the proliferation of tumor cells such as myeloleukemia cells and induce the differentiation of these cells into normal cells, is thus useful as an antitumor agent and additionally can manifest its effect for many hours. Further, the compound of this invention is useful also as a curative medicine for rheumatism and psoriasis.